# Re-write equation without multiplication

#### sfspitfire23

Hi guys,

I have an equation y = a*b + c*d

The variables are just real numbers. How can I get this equality to hold without multiplying anything together? I have tried taking the log of each side but that doesn't work.

Anyone have any thoughts?

#### Soroban

MHF Hall of Honor
Hllo, sfspitfire23!

Are you sure of the wording of the problem?
I don't think it can be done.

Rewrite without multiplication: .$$\displaystyle y \:= \:ab + cd$$
The variables are real numbers.

It might help if we knew what course this problem came from.

If the variables were natural numbers, the task can be completed.

. . $$\displaystyle \text{For example: }\:a\cdot b \;=\;\underbrace{b + b + b + \cdots + b}_{a\text{ terms}}$$

But with real numbers . . . I see no way to rewrite$$\displaystyle \pi\sqrt{3}$$

#### sfspitfire23

Just a linear algebra course. My teacher wants to know whether it can be done. I don't think it can.